Hermetically sealed containers with unitary closures are known in the art. Generally, such containers are fabricated using apparatus and methods for forming, filling, and sealing as disclosed generally in U.S. Pat. Nos. 3,597,793; 3,919,374; 4,239,726; 4,298,045; and U.S. Pat. No. Re. 27,155, as well as in the patents cited in these patents. Such sealed containers of unitary construction may be provided with a closure that can be severed to permit removal of the closure and to permit access to the contents in the container. Containers of this general type are well suited for sterile and aseptic packaging of various liquids.
A number of designs that have been proposed for unitary containers with severable closures typically employ a frangible web to join the closure or cap portion with the container. Tabs or other members may be provided on the closure or cap portion to enable the structure to be conveniently gripped with sufficient leverage so that the container can be easily opened by twisting off the cap portion. Examples of such designs are disclosed in U.S. Pat. Nos. 4,298,045, 4,258,867, and 4,239,726.
It is also known to provide a solid stopper which is partially encapsulated in place in an opening in a molded thermoplastic container. See for example U.S. Pat. No. 4,226,334. Another design for a container with a solid stopper partially encapsulated at the bottom of a container is disclosed in U.S. Pat. No. 3,919,374.
Although the above-discussed containers may be satisfactory for the applications for which they were designed, it would be desirable to provide an improved container having advantages not found in such conventional designs. Specifically, when containers having a frangible web and severable cap portion are used to collect samples that subsequently need to be shaken or agitated, it would be advantageous to provide a container structure that could accommodate a secondary seal or temporary closure after the hermetically sealed cap portion has been removed. The present invention provides such a container.